Skip to main content

Full text of "Text Book Of Mechanical Engineering"

See other formats


Driving Pull of Belts.

529

T
TABLE OF LOGARITHMS OF —?

Tn
 -      L°g
 1
	Tn
 £  :   L°g
		Tn tn
	Log

l£    I    '09691
	3i
	"54407
	5l
	75966

1^  ;  '17609
	3f
	•57403
	6
	77815

rf    <243°3
	4
	•60206
	*i
	79588

2     -30103
	4i
	•62840
	6i
	'81291

2|     -35218
	4.V
	•65321
	6}
	•82930

2i   '39794
	j  43
	•67670
	7
	•84509

2I : "43933
	5
	•69897
	10
	I'OOOOO

3  : -47712
	si
	•72016
	IOO
	2*00000

3i ! '5^88
	si
	•74036
	300
	2-47712

Driving Pull and H. P.—If two weights are slung over a
pulley, as in Fig. 531, the pull on the rim of the latter will be due

to their difference, wl - w, and as this is the same case as a
driving belt,            Driving pull = Tn - /„

and H. P. transmitted =

33000

But V = 27rRN

.-, H.P.

33°°°

Strength of Belting, allowing for the joint, may be taken.

so that

/"^(safe) •« 320 Ibs. per sq. in.

and the thickness varies from -^" to f" in single-ply belts.    The
width must be made sufficient to meet Tn.